Please use this identifier to cite or link to this item: https://hdl.handle.net/2440/45318
Type: Conference paper
Title: Fluvial response to climate and sea-level change: implications from the Skeleton Coast, Namibia.
Author: Krapf, Carmen Barbara Elke
Stollhofen, H.
Werner, Mario
Citation: 8th International Conference on Fluvial Sedimentology, 7-12 August, 2005: pp. 166.
Issue Date: 2005
Conference Name: International Conference on Fluvial Sedimentology (8th : 2005 : Delft, The Netherlands)
School/Discipline: Australian School of Petroleum
Statement of
Responsibility: 
Krapf, C.B.E. Stollhofen, H. and Werner, M.
Abstract: The Cenozoic climate of southern Africa has been a subject to influences of both global and regional nature. Orbitally controlled cycles, stepwise global coolings, the evolution of the ocean current system and differential uplift have dominantly influenced the climate history during the last 65 million years. The interplay between these factors has been complex, and the resulting climatic history is known only in a very broad outline for most of the Early Cenozoic. More is understood of Neogene climates because of the better preservation of terrestrial proxy data, but it is only over the last two glacial cycles that sufficient palaeoclimatic data have been assembled to allow a tentative picture of the regional patterns of change to be drawn. Data sets of oxygen isotope records from ocean sediment cores taken off the KwaZulu-Natal coast show that the climate of the southern African subcontinent has oscillated in a manner similar to that over much of the globe during the Middle and Late Pleistocene. Glacial and interglacial conditions occurred with a quasi-periodicity of about 100,000 years in response to Milankovitch forcing due to changes in the eccentricity of the earth’s orbit. The period from 125.000-16.000 BP was characterized in high latitudes by a series of pronounced rapid warmings, followed by slow variable declines to progressively lower minima, as the deuterium isotopic record from the Antarctic Vostok ice core illustrates. Proxy data sets show that similar variations occurred throughout southern Africa. However, a chronostratigraphic control on marine and continental Cenozoic deposits for the Namib Desert, especially for its northern part, is largely missing. Most data derived from continental deposits distributed across the Namib Desert and adjacent areas. But there is a lack of sedimentological and chronostratigraphical data from deposits of the mouth areas of the ephemeral river systems and from adjacent marine terraces. The Skeleton Coast in NW Namibia hosts a number of superbly exposed Cenozoic sedimentary successions, which provide a unique insight into the Cenozoic stratigraphy along the southwest African coastline. These deposits record the interplay of marine, fluvial and aeolian processes and therefore represent prime research objects to study fluvial response to sea-level and climate change. Along the incised banks of the ephemeral rivers and especially the wave cut seacliffs several fluvially dominated unconformity bounded sequences are exposed. Some of the rivers have built up braided river dominated fans on the coastal plain, e.g. the Koigab River. Pleistocene beach deposits form intermittent strips and ridges trending more or less parallel to the coast representing elevated shorelines. They consist of largely unlithified marine sand, gravel and boulder beds which attain thickness of up to 10 m. They are distributed along the coast to the north of the river outlets due to the extreme wave and wind action associated with the strong north trending Benguela Current. The elevations of these coastal terraces range from +2 to +35 m asl. and are located up to at least 5 km inland and reflecting eustatic highstands during the Late Tertiary to Quaternary.
Appears in Collections:Australian School of Petroleum publications

Files in This Item:
There are no files associated with this item.


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.